What is the treatment for hypotension?

Treatment for Hypotension

Hypotension treatment must be immediately directed at the underlying physiological cause—vasodilation, hypovolaemia, bradycardia, or low cardiac output—rather than reflexively administering fluids, as only approximately 50% of hypotensive patients are fluid-responsive. 1, 2

Initial Assessment: Identify the Underlying Cause

The most critical first step is determining which physiological derangement is causing hypotension, as treatment differs fundamentally based on etiology 1, 2:

• Vasodilation → Treat with vasopressors
• Hypovolaemia → Treat with intravascular fluids (only if fluid-responsive)
• Bradycardia → Treat with anticholinergics or chronotropes
• Low cardiac output → Treat with positive inotropes

Assess Fluid Responsiveness Before Giving Fluids

Perform a passive leg raise (PLR) test before administering fluids to determine if hypovolaemia is contributing to hypotension. 1, 2

• An increase in cardiac output after PLR strongly predicts fluid responsiveness (positive likelihood ratio = 11; 95% CI, 7.6-17; pooled specificity 92%) 1
• No increase in cardiac output after PLR indicates the patient will likely not respond to fluid (negative likelihood ratio = 0.13; 95% CI, 0.07-0.22; pooled sensitivity 88%) 1

Cause-Directed Pharmacological Treatment

For Vasodilation

• Norepinephrine is the first-line vasopressor for hypotension caused by vasodilation 2, 3
• Phenylephrine is best for hypotension with tachycardia, as it causes reflex bradycardia 1

For Hypovolaemia

• Administer intravascular fluids (crystalloid, colloid, or blood products) only if PLR test is positive 1
• Initial fluid bolus: 250-500 mL in adults 2
• In pediatric patients: 10-20 mL/kg (maximum 1,000 mL) normal saline 1
• Avoid additional fluid boluses in patients with cardiac dysfunction or volume overload signs (pulmonary edema) 1, 2

For Bradycardia

• Atropine or glycopyrronium is recommended as first-line treatment 1, 2
• If refractory, use epinephrine or isoprenaline 1
• Consider pacing for profound bradycardia 1

For Low Cardiac Output

• Dobutamine is recommended for low cardiac output from myocardial dysfunction 1, 2
• Epinephrine is an alternative for myocardial dysfunction 2, 4
• In acute heart failure with hypoperfusion, levosimendan is preferable over dobutamine to reverse the effect of beta-blockade, but it is not suitable for patients with systolic blood pressure < 85 mmHg or cardiogenic shock unless combined with other inotropes or vasopressors 5

Blood Pressure Targets

Maintain mean arterial pressure (MAP) ≥60 mmHg in at-risk patients, as MAP <60-70 mmHg or systolic BP <90-100 mmHg is associated with acute kidney injury, myocardial injury, myocardial infarction, and death 5, 1

• Increase MAP targets when venous or compartment pressures are elevated—add roughly the compartment pressure to your MAP target 5, 1, 2

Context-Specific Modifications

Trauma Without Brain Injury

• Use a restricted volume replacement strategy targeting systolic BP 80-90 mmHg (MAP 50-60 mmHg) until major bleeding is controlled 1, 2
• Aggressive fluid resuscitation in trauma without brain injury increases mortality 1, 2

Severe Traumatic Brain Injury

• Maintain MAP ≥80 mmHg to ensure adequate cerebral perfusion 1, 2
• Do not use permissive hypotension in traumatic brain injury 1, 2

Acute Heart Failure

• In patients with acute heart failure and signs of hypoperfusion, diuretics should be avoided before adequate perfusion is attained 5
• Beta-blockers should be used cautiously if the patient is hypotensive 5
• Inotropic agents are not recommended in hypotensive acute heart failure where the underlying cause is hypovolaemia or other potentially correctable factors before elimination of these causes 5

Monitoring Recommendations

• Continuous intraoperative arterial pressure monitoring reduces severity and duration of hypotension compared to intermittent monitoring 5, 1, 2
• Monitor ECG and blood pressure when using inotropic agents and vasopressors, as they can cause arrhythmia, myocardial ischaemia, and hypotension 5
• Titrate vasoactive agents to effect rather than using fixed doses, and avoid abrupt withdrawal of vasopressor infusions; reduce gradually 1

Critical Pitfalls to Avoid

• Do not reflexively give fluids without assessing fluid responsiveness—approximately 50% of hypotensive patients are not hypovolemic and require correction of vascular tone or inotropy instead 1, 2
• Postoperative hypotension is often unrecognized and may be more important than intraoperative hypotension because it is often prolonged and untreated 5, 1
• When treating intraoperative hypertension, do so carefully to avoid hypotension 5